Field discharge switch



INVENTOR cZZ r ws/W 3 [ATTORNEY p x //f N w O R B M lw 8 2 9 1 2 d O FIELD DISCHARGE SWITCH Filed Jan. 23 I WITNESSES:

Patented Oct. 2 1928.

{STATES PAT NTporrice' ems I. smwvwn, or 'rmsnunen, mE NsYLvAmA, .nssrenoa mo wnszmzeimusa AND MANUFKCTURINGGOMBANEYyAflORPORATIOiN 01 BENNSYLVANIA.

rmmifimscnmeniswmcni Applicationflled JanuaryZS, 1920 Serial m, 35 3;405.

My-invention relates to switches and particularly to switches employed in, protecting the field-magnet windings of dynamo-electric machines or other circuits having relatively hi h inductance.

One ,oj ject of my einvention is to provide a switch that/shall have means whereby one circuit-maybe completed before a second circ'uit is quickly interrupted.

Another object of my invention is tolprovidea switch, of theabove indicate'dcharactor, .that shall be compact in "structure, durable in service, and economical to manufacture. i

The introduction of-a second circuit before breaking the'first maybe desirable'for a-number of purposes; for example, so inserting a high-resistance resistor in the Ifield Tmagnet windings of a dynamo-electric machine that the current induced 'infthe field windings, WihenI'the ;field-'magnetf-winding circuit is broken, 1s'r1 ge1 expended in the resistor. Thistfunction-mayalsobe usedfto introduced a secondary {lighting system, when the main lighting system is de-energized; or'tointroduce a dynamoielectric machine before "deenergizing one whichis-in operation.

Inview, ofithe above, I provideasingle s operatin handle,1sW:itchmembersandmeans connected therebetweento effectthe relative- 1y quick operation of one of the'switch members ma the closuretof the other switch member. I

Fora better understanding of my invention, rdference maybemade to the accompanying drawings, of which Figure 1 is a view, partially in elevation and partially in section, of a switch embodying my invention; Figs. 2, 3, and 4 are sectional views of the same, taken along the lines IIII, III-III and IVIV, respectively, of Fig. 1, and Fig. 5 is a diagrammatic view, showing the locationof my switching device in circuits which include the field-magnet winding of a dynamo-electric machine Referring particularly toFig. 1, a cylindrical casing 1 of non-conducting material is mounted upon a slab or panel 2 of slate or other suitable material and is divided, by discs 3, 4 5, and 6,'into three compartments 7, 8, and 9. A shaft is mounted in an opening 11 in the slab 2 and is journaled in the discs 3 and 4. Contact members 12 of arcuate shape are attached to the shaft 10 by a clamping member 13 and screws 14 and may engage resilient contact fingers 15"when the shaft 10 is turned. A crank arm lfi is see cured to the inner end of the shaft 10 that ex tends into the compartment 8. a 3 A shaft17 is mounted" in the compartment Qand'is journaled in the discsfi and 6 Co nl tact members 18, are'attac'hedto the shaft '17 b'ya clampingmember 19; and screws 20 and they may engage resilient, contact lingers 21 when the shaft 171s turned.v A crankarm 22is secured to the end of the, shaft 17 that extends intofthe compartmentf8;

One end of a spring 23isa'ttahedto aprojection 24 of the arm IGaIid -theother end ofthe spring is attached 'tOapr jection 25 ofthearml2. An operating handle 26 .is secured to the outerend of the shaft '10 by-a screw 27. 2X dialplate28 anda nameplate 29 are mounted on the slab2 between it and the ."handle ilti. The discs 3, 4, 5, and '6 are'secured'to {the netizableplates 34 are secured'to theshaffi-IZ and are insulated therefrom "by the' tlibe 31. Plates'35 oflsuitable non-conductingmaterial are'mounte'd onitheshaft and serveto-fin sula'tethe "contact members 18fromtlre'plates 34 and a' magnetizable bar 36, that is positioned between the two central plates 35.

Referring particularly to Fig. 2, the contact member 12 is shown rigidly mounted.

member 13 and the screws 14 and insulated therefrom by the tube 31. The resilient contact fingers 15 are stiffened by braces 37 of arcuate shape and are secured to the casing 1 by the screws 38 and nuts 39, which also constitute binding posts.

Referring particularly to Fig. 3, the-shafts 10, and 17 are substantially in alignment. The arm 16 is secured to the shaft 10 byrthe pin 40 and is limited, in its turning movement, by the rim of disc 4, as shown in Fig. 3. The arm 22 is limited in its turning movement by the-rim of disc 5. As the arm 16 is turned from its position shown by solid lines to its position shown by broken lines, the

upon the shaft 10 by means of the clamping spring 23 is first elongated, and as it passes beyond the center line of the arm 22, it snaps the arm 22 to its position shown by the broken lines.

Fig. 1 shows one of the contact members 18 and one of the fingers 21. Their shape is such as to insure a good contact when they are engaged and a quick break when the switch is opened. The position of the contact members and the contact fingers, when the circuit is open, is shown by broken lines.

Referring particularly to Fig. 5, the contact members 18 and the contact fingers 21 are shown in a circuit which includes a dynamoelectric machine 42 and its field-magnet winding 13. The contact members 12 and the contact fingers 15 are shown in a secondary circuit which includes the field winding 43 and a resistor 4E4.

The switching device, as shown in Fig. 1 and Fig. 2, and by the solid lines in Fig. 3 and Fig. 4, has the circuit that is connected to the contact fingers 15 open and that connected to the contact fingers 21 closed. If the handle 26 be turned clockwise, the contact members 12 are turned clock-wise until they engage the contact fingers 15, and the arm 16 is turned until it is stopped by the rim of the disc 4.

After a good contact has been made between the contact members 12 and the contact fingers 15, the spring 23, which has been elongated, jerks the arm 22 around into the position that is shown by broken lines in Fig. 3. The rapid movement of the arm 22 actuates the shaft 17 and quickly breaks the engagement between the contact members 18 and the contact fingers 21. This disengagement occurs with great speed.

By turning the handle counter-clockwise, so that the contact members 12 become disengaged from the contact fingers 15, the arm 16 is turned counter-clockwise from the position shown by broken lines in Fig. 3 to its first position shown by solid lines. The reverse movement of the arm 16 elongates the spring 23, which rapidly returns the arm 22 to its original position shown in Fig. 3, when the arm 16 turns beyond the longitudinal axis of the arm 22, which is shown by broken lines.

The reverse movement of the arm 22 rapidly turns the contact member 17 from its position shown by broken lines in Fig. 1, to its first position shown by solid lines, thereby engaging the contact fingers 21.

The blow-out coil 33, the magnetizablc plates 34, the magnetizable bar 36, and insulating plates 35 serve to prevent arcing between the contact members 18 and the contact fingers 21, when the switch is being opened or closed.

From the description ofmy invention, it is apparent that it provides a ready means of closing one circuit before opening another circuit and that the one circuit is opened and closed with great rapidity.

lVhile I have shown my invention in a preferred form, it may be subjected to slight modifications, therefore, I desire to be limited only by the scope of the appended claim.

I claim as my invention: 7

In an electric switching device, the combination with a holding member provided with two end compartments and one central compartment, of a switch member rotatably mounted in one of the said end compartments, a means external to the said holding member for operating the said switch member, an arm rotatably mounted in the central compartment and coacting with the said switch memher, a second switch member rotatably mounted in the opposite end compartment, a second arm rotatably mounted in the said central compartment and coacting with the said second switch member, and a resilient means attached to the said arms for ensuring coaction thereof. I

In testimony whereof, I have here mto subscribed my name this 9th day of January,

' JAMES M. BRQWN 

